(a) Field of the Invention
The present invention relates to an integrated apparatus for supplying ink and regulating pressure, and more particularly, to an integrated apparatus for supplying ink and regulating pressure, in which proper negative pressure can be kept in a chamber accommodating the ink to stably form a meniscus in a nozzle.
(b) Description of the Related Art
In general, an inkjet printer is an apparatus that prints an image with predetermined colors by discharging a minute droplet of ink to a desired position on recording paper. The inkjet printer is provided with an ink transfer system for discharging the ink. The ink transfer system is broadly classified into two types according to methods of discharging the ink. One is a thermal driving type that uses a heat source to generate bubbles in ink and discharges the ink by the expansive force of the bubbles. The other one is a piezoelectric type that uses transformation of a piezoelectric body to discharge ink by pressure applied due to the transformation.
FIG. 1 is a schematic view showing an example of a conventional ink transfer system.
Referring to FIG. 1, an ink transfer system includes a main chamber 10 preliminarily accommodating a large amount of ink 1, a remote chamber 20 accommodating the ink 1 to be used in a printing job, and a nozzle 30 communicating with the remote chamber 20 and jetting the ink transferred from the remote chamber 20 to the outside. The ink 1 is transferred from the main chamber 10 to the remote chamber 20 via a control valve 12 and a filter 24. The amount of ink 1 accommodated in the remote chamber 20 is sensed by a level sensor 22 installed in the remote chamber 20 so that the amount of ink 1 transferred from the main chamber 10 to the remote chamber 20 can be controlled.
Even while the printing job is not performed, the ink 1 is remained in the remote chamber 20, the nozzle 30 and a channel 26 connected between the remote chamber 20 and the nozzle 30. To prevent the ink 1 in the nozzle 30 from being discharged to the outside while the printing job is not performed, the remote chamber 20 has to internally keep negative pressure lower than the atmospheric pressure. To this end, a vacuum pump 40 or the like is connected to the remote chamber 20 and keeps the remote chamber 20 in the negative pressure lower than the atmospheric pressure.
However, the conventional ink transfer system additionally needs the vacuum pump or the like for keeping the remote chamber in the negative pressure, so that it is inconvenient to separately install the additional device. Further, vibration generated when the vacuum pump operates is transmitted to the system, so that there is a problem in precisely controlling the discharge of the ink. Also, the vacuum pump is so distant from the remote chamber that a problem arises in response time delay. Furthermore, a separate pump is needed to supply ink from the main chamber to the remote chamber.